Aneuploidy and genetic variation in the Arabidopsis thaliana triploid response
Aneuploidy and genetic variation in the Arabidopsis thaliana triploid response
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DOI：
10.1534/genetics.104.037788
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发表时间：
2005-08-01
期刊：
影响因子：
3.3
通讯作者：
Comai, L
中科院分区：
文献类型：
--
作者：
Henry, IM;Dilkes, BP;Comai, L
多倍体，即每个细胞有两个以上基因组拷贝的遗传，在高等植物的进化中起着重要作用。人们对二倍体向多倍体的转变知之甚少，但在某些物种中，三倍体被认为是这种转变的中间体。相比之下，在其他物种中，三倍体被视为一个块。研究了拟南芥对三倍体的响应。通过比较二倍体col0与自然同源四倍体（Wa-1）或诱导的col0四倍体杂交产生的三倍体，检验了遗传变异的作用。在这项研究中，我们证明了拟南螺旋体的三倍体是可育的，产生一群不同的非整倍体。将三倍体的后代繁殖几代，产生二倍体和四倍体群体。这表明，在拟南芥中，三倍体可以很容易地形成四倍体，并作为整倍体类型之间的桥梁。对由三倍体产生的重组自交系的遗传分析发现，在1号染色体上有一个等位基因偏倚的位点，在四倍体系中有，而在二倍体系中没有。因此，遗传变异受制于最终倍性的选择，并可能在延长的非整倍体阶段起作用。
Polyploidy, the inheritance of more than two genome copies per cell, has played a major role in the evolution of higher plants. Little is known about the transition from diploidy to polyploidy but in some species, triploids are thought to function as intermediates in this transition. In contrast, in other species triploidy is viewed as a block. We investigated the responses of Arabidopsis thaliana to triploidy. The role of genetic variability was tested by comparing triploids generated from crosses between Col-0, a diploid, and either a natural autotetraploid (Wa-1) or an induced tetraploid of Col-0. In this study, we demonstrate that triploids of A. thaliana are fertile, producing a swarm of different aneuploids. Propagation of the progeny of a triploid for a few generations resulted in diploid and tetraploid cohorts. This demonstrated that, in A. thaliana, triploids can readily form tetraploids and function as bridges between euploid types. Genetic analysis of recombinant inbred lines produced from a triploid identified a locus on chromosome I exhibiting allelic bias in the tetraploid lines but not in the diploid lines. Thus, genetic variation was subject to selection contingent on the final ploidy and possibly acting during the protracted aneuploid phase.